Method for Repeatable Post Cure Dye for Organic Coatings

ABSTRACT

A method and apparatus by which specially electroplated and electrocoated items may be post cured dyed any suitable color using a fast and easy process is provided. The color of the item can be changed as often as desired by removing the dye and repeating the post cured dying process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/783,223, filed Mar. 17, 2006. The disclosure of this Provisional Patent Application is incorporated by reference herein in its entirety.

BACKGROUND

1. Field of Use

The present invention relates generally to the field of electrocoatings and more specifically to repeatable post cure dye process for organic coatings.

2. Description of Prior Art (Background)

Existing technology requires that to achieve a particular colored coating, the dye has to be blended with the electro coat chemistry. This means that if a manufacturer wants to market a product in 6 colors, the manufacturer is required to purchase 6 expensive electro coat systems. It will be appreciated that post cure dyeing would allow the manufacturer the cost savings of purchasing one system to deposit a clear coating and dyeing the product with whatever color was selling or otherwise in demand. Further cost savings could be realized in inventory reduction and elimination of unsold stock. Post cure dying would also allow the manufacturer to inventory only clear-coated product rather than multiple quantities of different colors because the product could be quickly dyed whatever color the sales orders required. Excess inventory due to a color going out of fashion would be eliminated and sales would be enhanced by the ability to introduce new colors quickly.

The prior art does not disclose a the ability to dye an electrocoat after the coating has been applied and oven cured remove the dye without harming the coating and re-dye the coating with another color. Previous art related to dyeing electrocoatings involved permanent application of the dye during the coating cycle. In the case of the prior art, the dye is blended into the electrocoat chemistry and applied with the coating, which is subsequently locked-in during the oven curing process. Once the coating is cured, the color is permanent and cannot be changed.

Color has been applied to aluminum objects by anodizing the aluminum and dyeing the anodized coating; and there is a process that will cause a colored oxide to form on some metals but in both cases the color cannot be changed and the coloring process is too complicated, expensive and dangerous to be done by the average consumer.

It will be appreciated therefore that there exists a need to be able to simply change colors of colored electrocoatings. It will also be appreciated therefore that there exists a need to expand the versatility of the electrophoretic coating by providing a cost effective way for users of the coating to produce colored products.

BRIEF SUMMARY

As will be described below, important aspects of the invention reside in the field of post dying and post bleaching previously dyed electrocoated items. One objective of the invention is to provide a method that will give the ability to color coordinate jewelry and fashion accessories with clothing.

In accordance with one embodiment of the present invention a method for post cure dyeing a metallic item coated with electrophoretic lacquer is provided The method includes plating the metallic item and post cure dying the metallic item coated with electrophoretic lacquer with at least one color dye.

The invention is also directed towards a portable dying kit for post cure dying a metallic item with electrophoretic lacquer, the portable dying kit includes a plurality of containers for preparing the metallic item to be dyed and a plurality of containers for preparing the metallic item to be bleached.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a method flow chart incorporating features of the present invention.

FIG. 2 is a method flow chart illustrating the plating and electrocoat process features of the present invention shown in FIG. 1;

FIG. 3 is a method flow chart illustrating the dyeing and dye removal process features of the present invention shown in FIG. 1; and

FIG. 4 is a perspective view of a portable dying apparatus in accordance with the invention described in FIG. 3.

DETAILED DESCRIPTION

Referring to FIG. 1 there is show a method flow chart illustrating the process by which suitable metal objects that have been properly electroplated and electrophoretically coated and cured 110, can be dyed virtually any desired color, subsequently stripped of the color and re-dyed with another color 120, in accordance with features of the present invention. It will be appreciated that the method described herein 120 may be done in the home by the consumer, and the color of the item, for example, jewelry, may be changed as often as desired by removing the dye and repeating the process.

Still referring to FIG. 1, in general, any suitable metallic item such as a necklace may be dyed or re-dyed. The metallic item is electroplated with a suitable pre-plate to be determined by the base metal of the object, where the purpose of the pre-plate is to promote adhesion of the nickel plate and seal any imperfections in the raw material. The metallic item is mechanically worked 101 to achieve a smooth finish after pre-plating.

The metallic item is then electroplated with a bright nickel layer to smooth out imperfections in the surface and improve luster. The item is then electroplated with a silver strike to promote adhesion of the subsequent bright silver electroplate 102 to maximize whiteness and reflectivity.

Next the item is electrocoated with a thin, clear electrophoretic coating, which has been properly cured 103. It will be appreciated that this coating is what is actually colored during the dye process. Cathodically applied electrophoretic coatings are preferred by any suitable organic coating may be used.

The finish developed in the plating process maximizes brilliance and light reflectivity through the coating. The coating allows a metal object to be dyed by providing a clear base for the dye. The dye process provides a simple application technique that anyone can use which allows a wide variety of colors to be achieved The dye removal process allows the object to be redyed as many times as desired.

Dye Application Procedure

Forming the dye solution—a suitable powdered dye is dissolved in water suitably hot enough to dissolve the powered dye. Typical dye concentration is 100-125 grams/liter but any suitable concentration of dye short of its physical saturation point can be used depending on how dark the desired color needs to be and how fast it is desired to saturate the coating. Typically, low concentrations of dye produce lighter colors and take longer to work; higher concentrations produce darker colors and saturate the coating faster. Suitable dyes include water-soluble azo and anthraquinone dyes in a variety of colors typically mixed with sodium chloride.

Still referring to FIG. 1: Applying the color dye solution—To apply the color, a part, such as a piece of costume jewelry properly prepared according to steps 101, 102, and 103, is immersed in a colored dye solution at a working temperature of approximately 180-220° F. The hotter the dye solution is, the faster the color develops. Immersion time is typically a few seconds to several minutes depending on temperature, concentration and desired hue, and will vary to some extent from color to color. Agitation of the solution or movement of the part may be necessary to promote uniform application of the dye, excess dye is rinsed off the part with suitably hot water, and a paper towel, or any suitably absorbent material, may be used to absorb most of the water from the part then use a hot air device, such as a hair dryer to finish drying the now colored part 104.

Dye Removal Procedure

Still referring to FIG. 1: Removing the dye—Immerse the previously dyed part in Dye Remover being careful to move the part around so that the dye is uniformly removed. Suitable dye removers include an alcohol to remove the dye from the coating without damaging it so that it can be dyed again. Isopropanol, ethanol and methanol have been successfully used in various concentrations. Cold water rinse When the color of the part changes to silver, remove it and rinse it off in suitably cold water. Hot water rinsing—Rinsing off any remaining dye remover with suitably hot water. Dying—a paper towel, or any suitably absorbent material, may be used to absorb most of the water from the part then use a hot air device, such as a hair dryer to finish drying the now colored part 105.

Turning now to FIG. 2, there is shown a more detailed method of the plating process, i.e., the electroplating, electrophoretically coating and curing method 110 shown in FIG. 1. The item or article 301 is degreased 302, rinsed 303, and cleaned 304. It will be appreciated that the base metal to be plated must be clean and free from dirt, oils, lacquer and the like. The article to be plated should be cleaned immediately before plating since oxidation will generally start to coat the surface within an hour, especially in the case of silver and copper. It will also be appreciated that each of the steps shown herein may be repeated more than what is shown in FIG. 2, and likewise in FIG. 3. For example, FIG. 2 indicates three separate rinse steps 305-307. It will be understood that any suitable number of rinse steps or other steps may be used.

Still referring to FIG. 2, the article is then acid activated 308 and rinsed again 309-311. Next is the cyanide copper strike 312, dragout 313, followed by another series of rinse steps 314-316. The article is again acid activated 317, rinsed 318-320. Next the article is bright nickel plated 312, dragged out 322, and rinsed 323-325. Next the article is silver-striked 326, dragged out, rinsed 328 and then bright silver plated 329. The article is dragged out 330 rinsed 331-332, neutralized 333 and rinsed again 334. Next the article is DI (de-ionized) rinsed 335-337 and pre-dipped 338. The article is electro-coated 339 and post dipped 340 before being DI rinsed 341 and 342. Finally, the last rinse is a hot DI water rinse 343 before being hot air dried 344. The article is then oven cured 345, after which it is ready 346 for the dying process shown in FIG. 3.

Turning now to FIG. 3, there is shown a more detailed method of the dying and re-dying method 120 shown in FIG. 1 where the prepared article (FIG. 2—item 346) can be dyed virtually any desired color, subsequently stripped of the color and redyed with another color.

If the article 346, prepared as shown in FIG. 2 is determined 202 not to have been dyed, then the article is immersed in a hot dye solution as described earlier until the color is satisfactory 205. Next the article is hot water rinsed 206 to remove all excess dye and then hot air dried 207 to produce the dyed article 208.

It will be appreciated that a wide range of colors are possible and the colors can be varied from very light pastels to deep hues simply by varying immersion time, dye concentration and solution temperature.

It is also possible to achieve a tie-dye effect by selectively immersing parts of the object in different color dyes. If the colors are overlapped, a rainbow like effect can be achieved where the colors meet.

If the article is previously prepared as shown in FIG. 2 and also previously dyed 208 then the dye is removed from the article by immersing the article in dye remover, as previously described, until the dye is removed from the article 203. Next the article is rinsed 204 and is again ready to be dyed as previously described, 205-208.

The plating and coating process make it possible to achieve a finish that is comprised of a thin, uniform, clear coating over a bright white background. This is a desired combination for producing vibrant dyed colors. The dyeing method described herein provides the ability to color the coating after curing. A key advantage to this method is that coloring of the coating takes place after the coating is cured. The dye removal chemistry bleaches the coating without harming it thereby allowing the coating to be colored again.

It will be appreciated that the present invention advantageously provides post cure dyeing which in turn allows the manufacturer to realize cost savings of purchasing one system to deposit a clear coating and dyeing the product with whatever color is currently in demand.

It will be appreciated that the dying and re-dying method described herein (FIG. 1, item 120) may be done in the home by the consumer. For example, referring to FIG. 4 there is shown a portable dying apparatus 10. The apparatus 10 is provided in a conventional attaché case 12. Inside the case 12 is a foam rubber block 14 overlaid with a sheet of plastic 16, both with cutouts for a plurality of polyethylene or other plastic containers 18, 20, 22, 24. Three solution bottles 32, 34 and 36 are provided containing a dye remover solution, a dye, and a cleaning solution, respectively. It will be understood that any suitable number of plastic containers and/or solution bottles may be provided.

Still referring to FIG. 4, a front panel 28 is provided. The front panel includes a timer 56, a switch 62 for selecting different power output levels for heating, via a heating element, dye solution in container 26. The electrical cord 30 is attached at 63. It will be appreciated that in alternate embodiments (not shown), the portable dying apparatus 10 may not include heating features and/or electrical power requirements.

It will be appreciated that features of the invention described herein also proved further cost savings which can be realized in inventory reduction and elimination of unsold stock. The invention allows the manufacturer to inventory only clear-coated products rather than multiple quantities of different colors because the product could be quickly dyed whatever color the sales orders required. Excess inventory due to a color going out of fashion would be reduced or eliminated and sales would be enhanced by the ability to introduce new colors quickly.

It should be understood that the foregoing description is only illustrative of the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. 

1. A method for post cure color dyeing a metallic item, the method comprising: plating the metallic item; and post cure dying the metallic item with at least one color dye.
 2. The method as in claim 1, wherein plating the metallic item comprises: mechanically finishing the metallic item for achieving a smooth shiny finish foundation for a bright finish; electroplating the metallic item with bright nickel; electroplating the metallic item with bright silver for maximizing light reflectance and finish whiteness; electrocoating the metallic item with electrophoretic lacquer; and oven curing the electroplated and electrocoated metallic item.
 3. The method as in claim 2 wherein rinsing the metallic item further comprises de-ionized water rinsing the metallic item.
 4. The method as in claim 2, wherein post cure dying the metallic item with at least one color dye comprises: immersing the electroplated and electrocoated metallic item metallic item in a hot dye solution, wherein the hot dye solution is approximately 180 to 220 degrees Fahrenheit; agitating the electroplated and electrocoated metallic item metallic item in the hot dye solution until the desired color is achieved.
 5. The method as in claim 4 further comprising: rinsing the dyed electroplated and electrocoated metallic item; and drying the dyed electroplated and electrocoated metallic item.
 6. The method as in claim 5 further comprising removing the dye from the dyed electroplated and electrocoated metallic item, wherein removing the dye from the dyed electroplated and electrocoated metallic item comprises immersing the dyed electroplated and electrocoated metallic item in a dye remover until the dye is removed from the dyed electroplated and electrocoated metallic item.
 7. The method as in claim 6 wherein removing the dye from the dyed electroplated and electrocoated metallic item further comprises post cure bleaching the metallic item, wherein post cure bleaching the metallic item further comprises solubilizing the at least one color dye.
 8. The method as in claim 1 wherein plating the metallic item further comprises: degreasing the metallic item; electro-cleaning the metallic item; acid activating the metallic item; cyanide copper striking the metallic item; rinsing the metallic item.
 9. A portable dying kit for post dying a metallic item coated with electrophoretic lacquer, the portable dying kit comprising: a plurality of containers for preparing the metallic item to be dyed; and a plurality of containers for preparing the metallic item to be bleached.
 10. The portable dying kit as in claim 9 further comprises at least one container for containing hot dye solutions approximately 180 degrees to 220 degrees, Fahrenheit.
 11. The portable dying kit as in claim 10 further comprising at least one heating element for heating solutions in the at least one container for containing hot dye solutions.
 12. The portable dying kit as in claim 9 further comprising at least one timing device. 